Phase Change 1

Learning Objective:
I will learn about phase changes.

 

DOL: Given 5 questions, I will identify how phase changes occur by determining which phases are involved in melting and evaporation, and explain how energy transfer is involved with 100% accuracy.

By Amanda Cooper

​R.C. -Let’s summarize what we know about the states of matter—solids, liquids, and gases. What are the key characteristics of each?

• Brief Recap: Matter is Anything That Takes Up Space

• States of Matter: Solid, Liquid, Gas

• Reminder: Solids Have a Definite Shape, Liquids and Gases Take Shape of Their Container

​Turn and Talk-

What do you think will happen when we heat different types of matter, like ice and water?

Multiple Choice

Now, let's observe what happens when we heat ice. When we add heat to ice, something interesting occurs. The ice starts to absorb the _________ from its surroundings.

Fill in the blank.

• heat
• pressure
• light
• cold

Multiple Choice

You have dropped your popsicle and are watching it become a LIQUID. Which answer BEST explains what PHASE CHANGE has occurred AND how the molecule MOVEMENT has changed? After you submit your answer create your own phase change similar to this one on your R.C.

• The PHASE CHANGE that has occurred is CONDENSATION and the molecule MOVEMENT has become FASTER.

• The PHASE CHANGE that has occurred is EVAPORATION and the molecule MOVEMENT has become SLOWER.

• The PHASE CHANGE that has occurred is MELTNG and the molecule MOVEMENT has become FASTER.

​

Annotate-
Observations: Ice to Water

• While the ice is melting, it's still the same substance, just in a different form. It's still made of water molecules, but now they're all sliding past each other instead of being stuck together like in ice.

• As long as there's still some ice left, it will keep melting until it's all turned into water. This process happens at a constant temperature until all the ice has melted.

• During melting, the shape of the ice starts to change too. Instead of being a solid block, it starts to spread out and take the shape of its container, just like water does.

Multiple Choice

Which answer BEST explain what molecule ARRANGEMENT tells us?

• Molecule ARRANGEMENT tells us how FAST or SLOW the atoms or molecules are moving.

• Molecule ARRANGEMENT tells us how CLOSE or FAR APART the atoms or molecules are to one another.

• Molecule ARRANGEMENT tells us how BIG or SMALL the atoms or molecules are compared to one another.

​Turn and Talk-
Describe the process going on in the pot.

Multiple Choice

At a special temperature, called the "boiling point," the water starts to turn into vapor. This change from liquid water to water vapor is what process?

• Evaporation
• Freezing
• Sublimation
• Condensation

Multiple Choice

You are relaxing on some grass when you notice LIQUID water droplets have begun to seemingly disappear off the grass leaves. Which answer BEST explains what PHASE CHANGE has occurred AND how the molecule ARRANGEMENT has changed?

• The PHASE CHANGE that has occurred is EVAPORATION and the molecule ARRANGEMENT has become FARTHER APART.

• The PHASE CHANGE that has occurred is FREEZING and the molecule ARRANGEMENT has become CLOSER.

• The PHASE CHANGE that has occurred is MELTING and the molecule MOVEMENT has become FASTER.

​Annotate -
Observations: Solid Metal

• When we add heat to the metal, something interesting occurs. The metal starts to absorb the heat from its surroundings.

• As more heat is added, the metal begins to warm up. It's like when you touch a metal spoon that's been sitting in a hot soup; the metal gets warmer.

• Unlike ice or water, solid metal doesn't change into a liquid or gas when it's heated. Instead, it expands.

• This expansion means that the metal gets a little bigger. It's like if you had a piece of clay and you stretched it out—it would get longer and maybe a bit wider.

  R.C.-What happens to metal when it is heated?

Open Ended

Even though the metal is expanding, it's still solid. It doesn't turn into a liquid or gas like water does when it's heated.

The shape of the metal stays the same as it expands. It doesn't take the shape of its container like liquids and gases do.

Why does the metal get hotter faster than the glass rod?

Draw

We observed the solid ice changing into liquid water when heat was added. This process is called melting, where a solid turns into a liquid.

Circle the phase change between solid and liquid.

Draw

When we heated the liquid water, it turned into water vapor, which is a gas. This process is called evaporation, where a liquid turns into a gas.

Circle the phase change where the liquid turns into a gas.

Poll

Review our predictions:

Were Our Predictions Correct?

• Yes

• No

Open Ended

Imagine you are conducting an experiment where you heat and then cool water. Before conducting the experiment, predict what will happen to the water when heat is added and when it is taken away. Describe your predictions for each stage of heating and cooling, including any changes in state of matter and the properties of water. Then, explain how these predictions relate to the concepts of solids, liquids, and gases that you've learned in class.

​DOL TIME!!

Do you best!